Energy efficiency of grain sorghum cultivation under different fertilizer systems

Abstract

Purpose. To study the influence of mineral and alternative organic-mineral fertilizer systems on energy efficiency of grain sorghum cultivation.Меthods. Field, analytical and statistical.Results. The results of studies on the effect of fertilizer systems on the energy efficiency of growing grain sorghum under conditions of sufficient moisture on loam leached black soil were presented. It was found that the use of fertilizers significantly increased the energy of the grain sorghum yield, was accompanied by a significant increase in energy consumption and led to a decrease in energy efficiency compared to the control without fertilizers.Conclusions. Grain sorghum has shown high energy efficiency for growing in conditions of sufficient moisture on the loamy leached black soil. On the natural fertility background grain sorghum plants formed the energy capacity of biological yield – 167 GJ/ha, energy consumption – 23,4 GJ/ha, Kee – 7,1. The use of mineral fertilizers significantly increased the energy capacity of the grain sorghum yield, but due to the significant increase in energy consumption was accompanied by a decrease in energy efficiency of its cultivation compared to the control without fertilizers. With the application of mineral fertilizers 180–360 kg/ha in the amount of NPK, the energy capacity of the crop yield compared to the control without fertilizers increased by 18–46 GJ/ha, energy consumption increased – by 8,3–14,7 GJ/ha, the energy efficiency coefficient decreased – by 1,3–1.5 units. The alternative organic-mineral fertilizer system has been determined to be more energy productive and more efficient than the mineral one. With the application of 4 t/ha of straw + 180–360 kg/ha of NPK, the energy efficiency compared to the application of only mineral fertilizers increased by 0.3–0.5 for absolute values of 6.1–6.2. Application of 4 t/ha of straw + N120P120K120 was defined the most energy efficient: yield of the crop – 236 GJ/ha, energy consumption – 38,8 GJ/ha, Kee – 6,1 with the advantage of energy capacity of the crop yield to control without fertilizer by 69 GJ/ha.